Various types of seed meters have been developed that use an air pressure differential, either vacuum or positive pressure, to adhere seed to a metering member. The metering member takes seed from a seed pool and sequentially discharges single seeds at another location. (In some cases, multiple seeds may be discharged at a time.) One common type of seed meter is shown in U.S. Pat. No. 5,170,909. There, a seed disk contained in a housing is used to meter the seed. A seed pool is positioned on one side of the disk at a lower portion thereof while vacuum is applied to the opposite side of the disk. As the disk is rotated, individual seeds from the seed pool are adhered by the vacuum to apertures that extend though the disk. When the seed reaches a desired release position, the vacuum is terminated, allowing the seed to drop from the disk.
In this and other configurations of seed meters (and other seed transport devices), it may be useful to ensure that seed doubles are eliminated. A seed double may occur, for example, when two (or more) seeds are captured by a single portion of a seed meter (e.g., a vacuum aperture of a seed meter) or device for transport between locations (e.g., between a seed pool and a release position for the seed). Because it may be desirable to plant (or otherwise process) only one seed at a time, it may be useful to provide an apparatus that eliminates such seed doubles.